NJ224 bearing: complete specifications & equivalents
The NJ224 is a ISO 15 radial bearing sized 120 x 215 x 40 mm (bore x OD x width). Verify dimensions against the official catalog before ordering.
Specification table
| Parameter | Value |
|---|---|
| Brand | NTN |
| Bore diameter d | 120 mm |
| Outer diameter D | 215 mm |
| Width B | 40 mm |
| Material | GCr15 |
| Seal / shield | open |
| Internal clearance | CN |
| Tolerance class | P0 |
| Cage | steel |
| Basic dynamic load rating C | 288 kN |
| Basic static load rating C0 | 320 kN |
| Fatigue load limit Pu | 33.5 kN |
| Limiting speed (mechanical) | 3200 rpm |
| Operating temperature | -40 to +120 °C |
| Mass | 5460 g |
| Manufacturer designation | NTN NJ224 |
| Standard | ISO 15 |
| Catalog version | NTN Ball and Roller Bearings CAT.No.2203E |
| Last verified | 2026-10-01 |
Source: catalog reference (NTN Ball and Roller Bearings CAT.No.2203E) · extracted 2026-10-01
Parameters extracted from the official NTN Ball and Roller Bearings catalogue (NTN Ball and Roller Bearings CAT.No.2203E); NTN® is a trademark of NTN Corporation, used here for identification only — mpnbase is not an authorized NTN distributor. Boundary dimensions are ISO 15 interchangeable; current production values may differ, verify at ntnglobal.com.
Dimensions in inches & NJ200-series range
| Bore d | 4.724 in |
|---|---|
| Outer diameter D | 8.465 in |
| Width B | 1.575 in |
| ISO bore code | 24 |
| Radial section height (D−d)/2 | 47.5 mm |
| Smallest bore in NJ200-series | 15 mm |
| Largest outer diameter in NJ200-series | 580 mm |
| Width range across NJ200-series | 11–92 mm |
| Bore position in NJ200-series (smallest first) | 22 of 36 |
| Bore above smallest NJ200-series size | 105 mm |
Cross references & equivalents
| Equivalent model | Brand | Match level | Note |
|---|---|---|---|
| NJ224-ECP | SKF | partial Main dimensions match; tolerances, seals or internal clearance differ. | Same 120×215×40 mm envelope per ISO 15; catalogue load ratings differ by >10% — re-rate the application before substituting. |
Interchange levels: full standard interchange · partial verify parameters · verify manual confirmation required. Links resolve to the equivalent model's specification page where available.
How the NJ224 model number is decoded
The NTN order number NJ224 denotes a 120×215×40 mm (4.724 × 8.465 × 1.575 in) cylindrical roller bearing in the NJ200 family, a pressed sheet-steel cage. The leading NJ defines the rib arrangement (inner ring two ribs + one outer rib); the dimension-series digits and the two-digit bore code resolve to 120 mm, with 215 mm OD and 40 mm width from the ISO 15 general plan. NTN ships these bearings open with normal (CN) radial clearance and P0 tolerance as standard; precision classes and C3/C4 clearance are separate order suffixes, not part of NJ224. Equivalent-load planning treats NJ224 as a pure radial bearing: keep P below 288 kN at the required L10, and let a paired angular-contact or thrust part carry any sustained axial component. The NJ design locates in one direction only: for two-direction location fit the matching loose rib ring (NUP execution) or pair the bearings back to back on the 120 mm shaft.
Typical equipment & failure modes
Common applications
- offshore drawworks and winch drums
- heavy press and large gearbox main shafts
- rolling-mill work-roll and backup-roll positions
- large turbine and generator rotor bearings
Known failure patterns
- roller smearing (microwelding) at start-up before the oil film builds under insufficient radial load
- pressed-steel cage pocket wear when rollers skid at light load or too-thin lubricant
- grease starvation and cage drag when relubrication intervals are extended past the grease life
- brinelling from static overload or impact during handling
- electrical pitting on VFD-driven motor shafts without grounding protection
Selection pitfalls — read before you substitute
- At 120 mm bore, oil-lubricated arrangements toward 3,700 r/min need positive flow and drain design; the 5460 g NJ224 ring stores enough heat that grease-only duty needs a careful relubrication calculation.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 215 mm race brinells and releases as vibration within hours.
- The 47.5 mm section at 120 mm bore leaves a narrow oil path; with the standard cage the relubrication groove and oil-level design must keep grease from churning in the 40 mm-wide cavity.
- Grease limiting speed 3,200 r/min and oil 3,700 r/min are different limits for NJ224: the first is the cage/lubricant mechanical ceiling, the second assumes real oil flow rather than an oil bath.
- Never press either ring through the roller complement when fitting: mounting force goes through the ring faces, or the 215 mm race brinells and releases as vibration within hours.
- The 288/320 kN ratings, 33.5 kN Pu and 5460 g mass are NTN Ball and Roller Bearings CAT.No.2203E values for NJ224 (standard execution); other makes sharing the ISO 15 envelope revise internal geometry without changing the order number, so keep the 2203E reference with the specification for critical drives.
Frequently asked questions
What are the dimensions and catalogue data of NJ224?
NJ224 is an NTN NJ single-row cylindrical roller bearing to ISO 15: 120 mm bore, 215 mm OD and 40 mm width (4.724 × 8.465 × 1.575 in). From NTN Ball and Roller Bearings CAT.No.2203E: C 288 kN, C0 320 kN, Pu 33.5 kN, grease limiting speed 3,200 r/min, oil 3,700 r/min, mass about 5460 g. It is open, with a pressed sheet-steel cage.
What is the difference between NU, NJ, NUP, N and NF cylindrical roller bearings?
The prefix states the rib arrangement: NU has two outer-ring ribs and a ribless inner ring (float, no axial load); NJ adds ribs for one-direction location; NUP adds a loose L-ring to locate both directions; N has two inner-ring ribs and a separable outer ring; NF has one rib per ring for one-direction guidance. NJ224 is two integral ribs on the inner ring and one rib on the outer ring — it locates the shaft in one axial direction.
What do the EA, E and ＊ suffixes mean on NTN cylindrical roller bearings?
EA is NTN's high-capacity design with a pressed sheet-steel cage and optimised roller complement in the same ISO 15 envelope; E marks the high-capacity design at the larger bores; the ＊ symbol printed before the code in the NTN catalogue marks the ULTAGE new-generation specification and is not typed as part of the order number. NJ224 is supplied in the standard open execution shown in the table.
Can NJ224 take axial load and locate a shaft?
the NJ design accepts axial load in one direction and provides one-way shaft location. For two-direction location use an NUP execution or an NJ pair with loose rib rings.
What do Fw and Ew mean for NJ224?
Fw is the inner sub-assembly raceway/roller-set envelope diameter and Ew the outer-ring raceway diameter printed for geometric checks: Fw 143.5 mm, Ew 191.5 mm. The nominal bore/OD remain 120/215 mm; Fw/Ew describe the rolling-contact path, and speeds still run to 3,200 r/min grease / 3,700 r/min oil.
Reviewed & verified by the MPN Base engineering desk against source catalog NTN Ball and Roller Bearings CAT.No.2203E on 2026-10-01. Read our editorial & correction policy.